Ultrasound uses echolocation for detection and imaging. Ultrasound machines utilize arrays of microphones and speakers to perform excitation and recording of echoes from the item being investigated. A signal including ultrasonic energy is transmitted through an ultrasound transducer in short bursts. After each burst, for a short period of time correlating to the amount of time for the ultrasonic energy to reach a target and reflect back to the transducer, the ultrasound machine receives reflected signals. Signals received during the short period undergo additional signal processing to determine the source locations of targets from which the signals reflected.
Traditional ultrasound systems have very high power requirements. One reason for the high power requirements is that these systems typically have 128 or more 12 or 14 bit analog-to-digital converters (ADCs) running at 40 Msps (mega samples per second) or more. In addition, in traditional systems, the beamformer is in the digital domain and consumes a great deal of power because it runs at the ADC sample rate for all 128 channels simultaneously.